Mice were given BPA in drinking water starting a week before pregnancy at levels calculated to produce a concentration the same as in a human mother. The dosing continued through pregnancy and lactation. Indicators of asthma showed up strongly in the BPA-exposed group, much more so than in the pups of the nonexposed mice.

"We also need to look at doing more epidemiological studies directly in humans, which is possible because BPA is so prevalent in the environment—all of us are already loaded with it to a varying extent. For example, it should be possible to determine if children who have more BPA exposure are more likely to develop asthma."